#!/bin/bash

# Configuration
LOG_FILE="script.log"
SCRIPT_NAME=$(basename "$0")

# --- Functions ---

# Function to display script usage
usage() {
    echo "Usage: $SCRIPT_NAME [OPTIONS]"
    echo "Options:"
    echo "  -h, --help       Show this help message"
    echo "  -v, --verbose    Enable verbose output"
    echo "  -a, --action     Specify an action (e.g., 'deploy', 'cleanup')"
    exit 0
}

# Function for logging messages
log() {
    local message="$1"
    local level="${2:-INFO}" # Default level is INFO
    timestamp=$(date +"%Y-%m-%d %H:%M:%S")
    echo "$timestamp [$level] $message" | tee -a "$LOG_FILE" >&2
}

# Function to handle errors
error_handler() {
    local exit_code="$?"
    local line_num="$1"
    local command="$2"
    if [ "$exit_code" -ne 0 ]; then
        log "ERROR: Command '$command' failed with exit code $exit_num on line $line_num." ERROR
        log "Script failed. Check $LOG_FILE for details." ERROR
        exit "$exit_code"
    fi
}

# --- Main Script Logic ---

# Enable strict mode:
# -e: Exit immediately if a command exits with a non-zero status.
# -u: Treat unset variables as an error when substituting.
# -o pipefail: The return value of a pipeline is the status of the last command to exit with a non-zero status,
#              or zero if no command exited with a non-zero status.
# -E: ERR traps are inherited by shell functions.
set -euo pipefail
set -E
trap 'error_handler $LINENO "$BASH_COMMAND"' ERR

VERBOSE=false
ACTION=""

# Parse command-line arguments
while (( "$#" )); do
    case "$1" in
        -h|--help)
            usage
            ;;
        -v|--verbose)
            VERBOSE=true
            log "Verbose output enabled." DEBUG
            ;;
        -a|--action)
            if [ -n "$2" ] && [ "${2:0:1}" != "-" ]; then
                ACTION="$2"
                shift
            else
                log "Error: Argument for $1 is missing." ERROR
                usage
            fi
            ;;
        *)
            log "Error: Invalid argument '$1'." ERROR
            usage
            ;;
    esac
    shift
done

log "Starting $SCRIPT_NAME..."

if [ "$VERBOSE" = true ]; then
    log "Verbose mode is ON." DEBUG
fi

if [ -n "$ACTION" ]; then
    log "Action specified: $ACTION"
    case "$ACTION" in
        deploy)
            log "Performing deployment tasks..." INFO
            # Add deployment logic here
            log "Deployment complete." INFO
            ;;
        cleanup)
            log "Performing cleanup tasks..." INFO
            # Add cleanup logic here
            log "Cleanup complete." INFO
            ;;
        *)
            log "Error: Unknown action '$ACTION'." ERROR
            usage
            ;;
    esac
else
    log "No specific action provided. Running default tasks." INFO
    # Add default script logic here
    echo "Hello, web developer!"
    # Example command that might fail
    # ls no_such_directory
fi

log "$SCRIPT_NAME finished successfully."
exit 0